The United States presidential election of 2004 was held on Tuesday, November 2, 2004. It was the 55th consecutive quadrennial election for the president and vice president of the United States. Republican candidate George Walker Bush, the President of the United States, defeated Democratic candidate John Kerry, the junior United States Senator from Massachusetts. This marked the first time in United States election history where the sitting president was re-elected after losing the popular vote (but winning the presidency) in the previous election. Bush not only finished first in the popular vote, but also became the first person since his father in 1988 to win an outright majority of the popular vote, and the first Republican candidate since him to win the popular vote. It was also a very active election. In 2004, Bush received more popular votes than any presidential candidate in history, and Kerry finished with the second most ever for a candidate in history. Foreign policy was the dominant theme throughout the election campaign, particularly Bush's conduct of the War on Terrorism and the 2003 invasion of Iraq.

As in the presidential election of 2000, voting controversies and concerns of irregularities emerged during and after the vote. The winner was not determined until the following day, when Kerry decided not to dispute Bush's win in the state of Ohio. The state held enough electoral votes to determine the winner of the presidency. Both Kerry and Democratic National Committee Chairman Howard Dean have stated their opinion that voting in Ohio did not proceed fairly, and that had it done so, the Democratic ticket might have won that state and therefore the election.

In the Electoral College, George W. Bush received 286 votes, John Kerry 251 and John Edwards 1 (see “Faithless elector” in Minnesota section of this article).